In "Love Hurts", Leo warned the sisters not to touch the arrow as it was poisonous. However, the poison does not affect witches. This could either be a mistake in writing or simply a mistake by Leo due to being badly poisoned and confused.

While the Charmed series is consistent in its use of the term "arrow" in regards to Darklighter Crossbows, projectiles fired from a crossbow are technically more accurately designated as "bolts" or "quarrels".